Search Results

An extracellular phosphoglycan (exPG), present in the culturem edium of the promastigote form L oefi shmania donovani, was purified and structurally characterized. The purification scheme included ethanol precipitation of the culture medium, anion exchange chromatography, hydrophobic chromatography on phenyl-Sepharose, and preparative polyacrylamgeild e electrophoresis. Structural analysis by ‘H-’H NMR, methylation linkage analysis, and glycosidase digestion revealed that the exPG consisted of thfoel lowing structure: (CAP)+[P04-6Galp@1-4Manpal]lo-11-POr6GalpB1-4Man. The capw as found to be ones eovf eral small, neutral oligosaccharides, the most abundant of which was the trisaccharide Galp@l-4(Manpal-2)Man. The results indicated structural analogy to the cellular-derived lipophosphoglycan (LPG) from L. donovani. The important exceptions are a lacko f the lipid anchor, the entire phosphosaccharide core, and several of the repeating disaccharide units. Although the function of exPGis presently unknowni,t may play a protective role for the promastigote in the insect vector or during infection of a mammalian host